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Cancer genomics has revealed many genes and core molecular processes that contribute to human malignancies, but the genetic and molecular bases of many rare cancers remains unclear. Genetic predisposition accounts for 5 to 10% of cancer diagnoses in children1,2, and genetic events that cooperate with known somatic driver events are poorly understood. Pathogenic germline variants in established cancer predisposition genes have been recently identified in 5% of patients with the malignant brain tumour medulloblastoma3. Here, by analysing all protein-coding genes, we identify and replicate rare germline loss-of-function variants across ELP1 in 14% of paediatric patients with the medulloblastoma subgroup Sonic Hedgehog (MBSHH). ELP1 was the most common medulloblastoma predisposition gene and increased the prevalence of genetic predisposition to 40% among paediatric patients with MBSHH. Parent-offspring and pedigree analyses identified two families with a history of paediatric medulloblastoma. ELP1-associated medulloblastomas were restricted to the molecular SHHα subtype4 and characterized by universal biallelic inactivation of ELP1 owing to somatic loss of chromosome arm 9q. Most ELP1-associated medulloblastomas also exhibited somatic alterations in PTCH1, which suggests that germline ELP1 loss-of-function variants predispose individuals to tumour development in combination with constitutive activation of SHH signalling. ELP1 is the largest subunit of the evolutionarily conserved Elongator complex, which catalyses translational elongation through tRNA modifications at the wobble (U34) position5,6. Tumours from patients with ELP1-associated MBSHH were characterized by a destabilized Elongator complex, loss of Elongator-dependent tRNA modifications, codon-dependent translational reprogramming, and induction of the unfolded protein response, consistent with loss of protein homeostasis due to Elongator deficiency in model systems7-9. Thus, genetic predisposition to proteome instability may be a determinant in the pathogenesis of paediatric brain cancers. These results support investigation of the role of protein homeostasis in other cancer types and potential for therapeutic interference.
Assuntos
Neoplasias Cerebelares/metabolismo , Mutação em Linhagem Germinativa , Meduloblastoma/metabolismo , Fatores de Elongação da Transcrição/metabolismo , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Criança , Feminino , Humanos , Masculino , Meduloblastoma/genética , Linhagem , RNA de Transferência/metabolismo , Fatores de Elongação da Transcrição/genéticaRESUMO
Smell deficits and neurobiological changes in the olfactory bulb (OB) and olfactory epithelium (OE) have been observed in schizophrenia and related disorders. The OE is the most peripheral olfactory system located outside the cranium, and is connected with the brain via direct neuronal projections to the OB. Nevertheless, it is unknown whether and how a disturbance of the OE affects the OB in schizophrenia and related disorders. Addressing this gap would be the first step in studying the impact of OE pathology in the disease pathophysiology in the brain. In this cross-species study, we observed that chronic, local OE inflammation with a set of upregulated genes in an inducible olfactory inflammation (IOI) mouse model led to a volume reduction, layer structure changes, and alterations of neuron functionality in the OB. Furthermore, IOI model also displayed behavioral deficits relevant to negative symptoms (avolition) in parallel to smell deficits. In first episode psychosis (FEP) patients, we observed a significant alteration in immune/inflammation-related molecular signatures in olfactory neuronal cells (ONCs) enriched from biopsied OE and a significant reduction in the OB volume, compared with those of healthy controls (HC). The increased expression of immune/inflammation-related molecules in ONCs was significantly correlated to the OB volume reduction in FEP patients, but no correlation was found in HCs. Moreover, the increased expression of human orthologues of the IOI genes in ONCs was significantly correlated with the OB volume reduction in FEP, but not in HCs. Together, our study implies a potential mechanism of the OE-OB pathology in patients with psychotic disorders (schizophrenia and related disorders). We hope that this mechanism may have a cross-disease implication, including COVID-19-elicited mental conditions that include smell deficits.
Assuntos
Modelos Animais de Doenças , Inflamação , Bulbo Olfatório , Mucosa Olfatória , Transtornos Psicóticos , Esquizofrenia , Animais , Mucosa Olfatória/patologia , Mucosa Olfatória/metabolismo , Transtornos Psicóticos/patologia , Camundongos , Humanos , Masculino , Inflamação/metabolismo , Inflamação/patologia , Bulbo Olfatório/patologia , Bulbo Olfatório/metabolismo , Feminino , Esquizofrenia/patologia , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia , Esquizofrenia/genética , Transtornos do Olfato/etiologia , Transtornos do Olfato/fisiopatologia , Olfato/fisiologia , Adulto , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Neurônios/patologiaRESUMO
Centrioles are submicron-scale, barrel-shaped organelles typically found in pairs, and play important roles in ciliogenesis and bipolar spindle assembly. In general, successful execution of centriole-dependent processes is highly reliant on the ability of the cell to stringently control centriole number. This in turn is mainly achieved through the precise duplication of centrioles during each S phase. Aberrations in centriole duplication disrupt spindle assembly and cilia-based signaling and have been linked to cancer, primary microcephaly and a variety of growth disorders. Studies aimed at understanding how centriole duplication is controlled have mainly focused on the post-translational regulation of two key components of this pathway: the master regulatory kinase ZYG-1/Plk4 and the scaffold component SAS-6. In contrast, how transcriptional control mechanisms might contribute to this process have not been well explored. Here we show that the chromatin remodeling protein CHD-1 contributes to the regulation of centriole duplication in the C. elegans embryo. Specifically, we find that loss of CHD-1 or inactivation of its ATPase activity can restore embryonic viability and centriole duplication to a strain expressing insufficient ZYG-1 activity. Interestingly, loss of CHD-1 is associated with increases in the levels of two ZYG-1-binding partners: SPD-2, the centriole receptor for ZYG-1 and SAS-6. Finally, we explore transcriptional regulatory networks governing centriole duplication and find that CHD-1 and a second transcription factor, EFL-1/DPL-1 cooperate to down regulate expression of CDK-2, which in turn promotes SAS-6 protein levels. Disruption of this regulatory network results in the overexpression of SAS-6 and the production of extra centrioles.
Assuntos
Proteínas de Caenorhabditis elegans , Centríolos , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ciclo Celular/genética , Centríolos/genética , Centríolos/metabolismo , Montagem e Desmontagem da Cromatina/genética , Proteínas Quinases/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Aging is associated with cell senescence and is the major risk factor for AD. We characterized premature cell senescence in postmortem brains from non-diseased controls (NDC) and donors with Alzheimer's disease (AD) using imaging mass cytometry (IMC) and single nuclear RNA (snRNA) sequencing (> 200,000 nuclei). We found increases in numbers of glia immunostaining for galactosidase beta (> fourfold) and p16INK4A (up to twofold) with AD relative to NDC. Increased glial expression of genes related to senescence was associated with greater ß-amyloid load. Prematurely senescent microglia downregulated phagocytic pathways suggesting reduced capacity for ß-amyloid clearance. Gene set enrichment and pseudo-time trajectories described extensive DNA double-strand breaks (DSBs), mitochondrial dysfunction and ER stress associated with increased ß-amyloid leading to premature senescence in microglia. We replicated these observations with independent AD snRNA-seq datasets. Our results describe a burden of senescent glia with AD that is sufficiently high to contribute to disease progression. These findings support the hypothesis that microglia are a primary target for senolytic treatments in AD.
Assuntos
Doença de Alzheimer , Senescência Celular , Transcriptoma , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Humanos , Senescência Celular/fisiologia , Senescência Celular/genética , Idoso , Masculino , Idoso de 80 Anos ou mais , Feminino , Microglia/patologia , Microglia/metabolismo , Encéfalo/patologia , Encéfalo/metabolismo , Peptídeos beta-Amiloides/metabolismo , Neuroglia/patologia , Neuroglia/metabolismoRESUMO
The early language environment, especially high-quality, contingent parent-child language interactions, is crucial for a child's language development and later academic success. In this secondary analysis study, 89 parent-child dyads were randomly assigned to either the Music Together® (music) or play date (control) classes. Children were 9- to 15-month old at baseline, primarily white (86.7%) and female (52%). Measures of conversational turns (CTs) and parental verbal quality were coded from parent-child free play episodes at baseline, mid-intervention (month 6), and post-intervention (month 12). Results show that participants in the music group had a significantly greater increase in CT measures and quality of parent verbalization post-intervention. Music enrichment programs may be a strategy to enhance parent-child language interactions during early childhood.
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Música , Humanos , Feminino , Pré-Escolar , Criança , Lactente , Linguagem Infantil , Relações Pais-Filho , Desenvolvimento da Linguagem , PaisRESUMO
BACKGROUND: Interventions that use the Health Action Process Approach (HAPA) model show promise for increasing PA frequency, duration, and intensity. However, there is limited understanding of how HAPA model variables have been operationalized for PA interventions in chronic disease to promote behavior change and sustained PA or whether the phase or continuous form of the HAPA model was used. The aim of this scoping review is to describe how the HAPA model variables for PA interventions were operationalized and provide details of implementation. METHOD: We searched five databases to identify studies published between January 1992 and March 2024. We aimed to describe (1) the characteristics of interventions including setting, delivery mode, duration, and content; (2) which HAPA variables were operationalized and the strategies used; and (3) the physical activity measures and outcome effects. RESULTS: The search identified 23 interventions in 30 papers (12 protocols, 3 quasi-experimental studies, and 15 randomized controlled trials (RCTs)). Seven of the 15 RCTs reported significant positive effects of the HAPA model on PA behavior outcomes. Interventions operationalized between three and nine HAPA constructs showed significant variability in how the HAPA model is used in intervention research. PA measures varied from self-report to validated objective instruments. CONCLUSION: We found a lack of clarity in decisions about which HAPA constructs were included in interventions. The wide variability in operationalized HAPA constructs made it challenging to compare interventions. Researchers should provide more detail about intervention design and implementation procedures to enhance transparency.
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Microbial eukaryotes (or protists) in marine ecosystems are a link between primary producers and all higher trophic levels, and the rate at which heterotrophic protistan grazers consume microbial prey is a key mechanism for carbon transport and recycling in microbial food webs. At deep-sea hydrothermal vents, chemosynthetic bacteria and archaea form the base of a food web that functions in the absence of sunlight, but the role of protistan grazers in these highly productive ecosystems is largely unexplored. Here, we pair grazing experiments with a molecular survey to quantify protistan grazing and to characterize the composition of vent-associated protists in low-temperature diffuse venting fluids from Gorda Ridge in the northeast Pacific Ocean. Results reveal protists exert higher predation pressure at vents compared to the surrounding deep seawater environment and may account for consuming 28 to 62% of the daily stock of prokaryotic biomass within discharging hydrothermal vent fluids. The vent-associated protistan community was more species rich relative to the background deep sea, and patterns in the distribution and co-occurrence of vent microbes provide additional insights into potential predator-prey interactions. Ciliates, followed by dinoflagellates, Syndiniales, rhizaria, and stramenopiles, dominated the vent protistan community and included bacterivorous species, species known to host symbionts, and parasites. Our findings provide an estimate of protistan grazing pressure within hydrothermal vent food webs, highlighting the important role that diverse protistan communities play in deep-sea carbon cycling.
Assuntos
Bactérias/isolamento & purificação , Carbono/metabolismo , Eucariotos/fisiologia , Fontes Hidrotermais/parasitologia , Microbiota , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Biodiversidade , Ciclo do Carbono , Eucariotos/classificação , Eucariotos/genética , Eucariotos/isolamento & purificação , Fontes Hidrotermais/microbiologia , Oceano Pacífico , Filogenia , Água do Mar/microbiologia , Água do Mar/parasitologiaRESUMO
Effortful control (EC), a self-regulation skill, is associated with long-term developmental outcomes. Music has been associated with infant self-regulation and may be an intervention strategy for enhancing EC during toddlerhood. This investigation included 32 parent-child dyads from a previously conducted randomized controlled trial (RCT). Participants (9-15-months old at baseline) attended either a music enrichment program or a playdate control once a week for 1 year and monthly for an additional year. At age 3, participants completed snack and gift delay effortful control tasks. Groups were compared using one-way ANOVA. We found that participants in the music group had a significantly higher score during snack delay (music mean = 3.47 ± 0.94; control mean = 2.45 ± 1.51; p = 0.03; Cohen's d = 0.84). We did not find a significant group difference for latency to peek (music mean = 39.10 ± 20.10; control mean = 30.90 ± 19.88; p = 0.25; d = 0.57) or latency to touch (music mean = 105.73 ± 417.69; control mean = 98.35 ± 28.84; p = 0.38; d = 0.29) for the gift task. This study provides initial evidence that early participation in a music enrichment program may benefit later development of EC. This study is registered at ClinicalTrials.gov (NCT02936284).
Assuntos
Música , Autocontrole , Pré-Escolar , Humanos , LactenteRESUMO
Single-celled microbial eukaryotes inhabit deep-sea hydrothermal vent environments and play critical ecological roles in the vent-associated microbial food web. 18S rRNA amplicon sequencing of diffuse venting fluids from four geographically- and geochemically-distinct hydrothermal vent fields was applied to investigate community diversity patterns among protistan assemblages. The four vent fields include Axial Seamount at the Juan de Fuca Ridge, Sea Cliff and Apollo at the Gorda Ridge, all in the NE Pacific Ocean, and Piccard and Von Damm at the Mid-Cayman Rise in the Caribbean Sea. We describe species diversity patterns with respect to hydrothermal vent field and sample type, identify putative vent endemic microbial eukaryotes, and test how vent fluid geochemistry may influence microbial community diversity. At a semi-global scale, microbial eukaryotic communities at deep-sea vents were composed of similar proportions of dinoflagellates, ciliates, Rhizaria, and stramenopiles. Individual vent fields supported distinct and highly diverse assemblages of protists that included potentially endemic or novel vent-associated strains. These findings represent a census of deep-sea hydrothermal vent protistan communities. Protistan diversity, which is shaped by the hydrothermal vent environment at a local scale, ultimately influences the vent-associated microbial food web and the broader deep-sea carbon cycle.
Assuntos
Fontes Hidrotermais , Microbiota , Água do Mar , Filogenia , Eucariotos/genética , Microbiota/genéticaRESUMO
Tumors of the central nervous system (CNS) are a leading cause of morbidity and mortality in the pediatric population. Molecular characterization in the last decade has redefined CNS tumor diagnoses and risk stratification; confirmed the unique biology of pediatric tumors as distinct entities from tumors that occur in adulthood; and led to the first novel targeted therapies receiving Food and Drug Administration (FDA) approval for children with CNS tumors. There remain significant challenges to overcome: children with unresectable low-grade glioma may require multiple prolonged courses of therapy affecting quality of life; children with high-grade glioma have a dismal long-term prognosis; children with medulloblastoma may suffer significant short- and long-term morbidity from multimodal cytotoxic therapy, and approaches to improve survival in ependymoma remain elusive. The Children's Oncology Group (COG) is uniquely positioned to conduct the next generation of practice-changing clinical trials through rapid prospective molecular characterization and therapy evaluation in well-defined clinical and molecular groups.
Assuntos
Neoplasias Encefálicas , Neoplasias do Sistema Nervoso Central , Neoplasias Cerebelares , Glioma , Meduloblastoma , Criança , Humanos , Qualidade de Vida , Neoplasias do Sistema Nervoso Central/terapia , Glioma/patologia , Meduloblastoma/patologia , Neoplasias Encefálicas/patologiaRESUMO
Persistence of chronic hepatitis B (CHB) is attributed to maintenance of the intrahepatic pool of the viral covalently closed circular DNA (cccDNA), which serves as the transcriptional template for all viral gene products required for replication. Current nucleos(t)ide therapies for CHB prevent virus production and spread but have no direct impact on cccDNA or expression of viral genes. We describe a potential curative approach using a highly specific engineered ARCUS nuclease (ARCUS-POL) targeting the hepatitis B virus (HBV) genome. Transient ARCUS-POL expression in HBV-infected primary human hepatocytes produced substantial reductions in both cccDNA and hepatitis B surface antigen (HBsAg). To evaluate ARCUS-POL in vivo, we developed episomal adeno-associated virus (AAV) mouse and non-human primate (NHP) models containing a portion of the HBV genome serving as a surrogate for cccDNA. Clinically relevant delivery was achieved through systemic administration of lipid nanoparticles containing ARCUS-POL mRNA. In both mouse and NHP, we observed a significant decrease in total AAV copy number and high on-target indel frequency. In the case of the mouse model, which supports HBsAg expression, circulating surface antigen was durably reduced by 96%. Together, these data support a gene-editing approach for elimination of cccDNA toward an HBV cure.
Assuntos
Hepatite B Crônica , Hepatite B , Animais , Antivirais , DNA Circular/genética , DNA Viral/genética , Dependovirus/genética , Hepatite B/terapia , Antígenos de Superfície da Hepatite B/genética , Antígenos de Superfície da Hepatite B/uso terapêutico , Vírus da Hepatite B/genética , Humanos , Lipossomos , Camundongos , Nanopartículas , Replicação ViralRESUMO
BACKGROUND: Parent-child interactions are linked to childhood obesity. Music enrichment programs enhance parent-child interactions and may be a strategy for early childhood obesity prevention. OBJECTIVE: We implemented a 2-year randomized, controlled trial to assess the effects of a music enrichment program (music, n = 45) vs. active play date control (control, n = 45) on parent-child interactional quality and infant weight status. METHODS: Typically developing infants aged 9-to 15-months were enrolled with a primary caregiver in the Music Together ® or a play date program. Participants attended once per week group meetings for 12 months and once per month group meetings for an additional 12 months. Parent-child interaction was measured using the Parent Child Early Relational Assessment (PCERA) at baseline, month 6, 12, and 24. We used a modified intent-to-treat mixed model regression to test group differences in parent-child interactions and Weight for length z-score (zWFL) growth trajectories were modeled. RESULTS: There were significant differential group changes across time for negative affect during feeding (group*month; p = 0.02) in that those parents in the music group significantly decreased their negative affect score compared with the control group from baseline to month 12 (music change = -0.279 ± 0.129; control change = +0.254 ± 0.131.; p = 0.00). Additionally, we also observed significant differential group changes across time for parent intrusiveness during feeding (group*month; p = 0.04) in that those parents in the music group significantly decreased their intrusiveness score compared with the control group from month 6 to month 12 (music change = -0.209 ± 0.121; control change = 0.326 ± 0.141; p = 0.01). We did not find a significant association between any of the changes in parental negative affect and intrusiveness with child zWFL trajectories. CONCLUSION: Participating in a music enrichment program from an early age may promote positive parent-child interactions during feeding, although this improvement in the quality of parent-child interactions during feeding was not associated with weight gain trajectories.
Assuntos
Música , Obesidade Infantil , Criança , Pré-Escolar , Humanos , Lactente , Obesidade Infantil/prevenção & controle , Pais , Relações Pais-Filho , Refeições , Poder FamiliarRESUMO
Older adults must have the ability to walk at variable speeds/distances to meet community demands. This single group pre-post test study's purposes were to examine if actual cadences after 7 weeks of rhythmic auditory stimulation gait training matched target cadences, improved walking distance, duration, velocity, maximum cadence, balance, enjoyment, and/or changed spatial/temporal gait parameters. Fourteen female adults (72.6 ± 4.4 years) participated in 14 sessions, while variable cadences were progressively introduced. Eleven older adult responders walked faster (3.8 steps/min) than one target cadence (-10% pace) while matching the target cadences for the other paces when walking with rhythmic auditory stimulation. Two nonresponders walked near their baseline cadence with little variability while one walked at faster cadences; all three did not appear to adjust to the beat of the music. After training, participants increased their walking distance, 90.8 ± 46.5 m; t(1, 13) = -7.3; p ≤ .005, velocity, 0.36 ± 0.15 m/s; t(1, 40) = -15.4; p < .001, and maximum cadence, 20.6 ± 9.1 steps/min; t(1, 40) = -14.6; p < .001; changes exceeded minimal clinically important differences. Twelve of 14 expressed enjoyment. Walk with rhythmic auditory stimulation training is a promising activity for older adults, which may translate to an individual's ability to adapt walking speeds to various community demands.
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Música , Humanos , Feminino , Idoso , Estimulação Acústica , Marcha/fisiologia , Caminhada/fisiologia , Velocidade de Caminhada/fisiologiaRESUMO
Adolescent disordered eating and obesity are interrelated and adversely relate to mental and metabolic health. Parental feeding practices have been associated with adolescent disordered eating and obesity. Yet, observable interactions related to food parenting have not been well characterized. To address this gap, N = 30 adolescents (M ± SD 14 ± 2 year) at risk for adult obesity due to above-average body mass index (BMI ≥70th percentile) or parental obesity (BMI ≥30 kg/m2 ) participated in a video-recorded parent-adolescent task to discuss a food/eating-related disagreement. Interactions were coded for individual/dyadic affect/content using the Interactional Dimensions Coding System. We examined associations of interaction qualities with parent-reported food practices, adolescent disordered eating behaviors/attitudes, and insulin resistance. Reported parenting practices were correlated with multiple interaction qualities (p-values <0.05), with the most consistent correspondence between parent-reported pressure to eat (e.g., pressure to eat more healthy foods) and negative aspects of parent-adolescent interactions. Also, after accounting for adolescent age, sex, and BMI-standard score, parent-adolescent interaction qualities were associated with adolescents' disordered eating and insulin resistance. Specifically, greater adolescent problem-solving related to less adolescent global disordered eating, shape, and weight concern (p-values <0.05); adolescent autonomy related to less weight concern (p = 0.03). Better parent communication skills were associated with less adolescent eating concern (p = 0.04), and observed dyadic mutuality related to adolescents' lower insulin resistance (p = 0.03). Parent-adolescent interaction qualities during food/eating-related disagreements show associations with parent-reported food practices and adolescent disordered eating. This method may offer a tool for measuring the qualities of parent-adolescent food/eating-related interactions. A nuanced understanding of conversations about food/eating may inform family-based intervention in youth at-risk for adult obesity.
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Transtornos da Alimentação e da Ingestão de Alimentos , Resistência à Insulina , Adulto , Humanos , Adolescente , Poder Familiar , Pais , Obesidade , Relações Pais-Filho , Inquéritos e QuestionáriosRESUMO
Response criteria for paediatric intracranial ependymoma vary historically and across different international cooperative groups. The Response Assessment in the Pediatric Neuro-Oncology (RAPNO) working group, consisting of an international panel of paediatric and adult neuro-oncologists, neuro-radiologists, radiation oncologists, and neurosurgeons, was established to address both the issues and the unique challenges in assessing the response in children with CNS tumours. We established a subcommittee to develop response assessment criteria for paediatric ependymoma. Current practice and literature were reviewed to identify major challenges in assessing the response of paediatric ependymoma to clinical trial therapy. For areas in which data were scarce or unavailable, consensus was reached through an iterative process. RAPNO response assessment recommendations include assessing disease response on the basis of changes in tumour volume, and using event-free survival as a study endpoint for patients entering clinical trials without bulky disease. Our recommendations for response assessment include the use of brain and spine MRI, cerebral spinal fluid cytology, neurological examination, and steroid use. Baseline postoperative imaging to assess for residual tumour should be obtained 24-48 h after surgery. Our consensus recommendations and response definitions should be prospectively validated in clinical trials.
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Neoplasias Encefálicas , Neoplasias do Sistema Nervoso Central , Ependimoma , Adulto , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/terapia , Neoplasias do Sistema Nervoso Central/patologia , Criança , Ependimoma/diagnóstico por imagem , Ependimoma/terapia , Humanos , Imageamento por Ressonância MagnéticaRESUMO
To better define roles that astrocytes and microglia play in Alzheimer's disease (AD), we used single-nuclei RNA-sequencing to comprehensively characterise transcriptomes in astrocyte and microglia nuclei selectively enriched during isolation post-mortem from neuropathologically defined AD and control brains with a range of amyloid-beta and phospho-tau (pTau) pathology. Significant differences in glial gene expression (including AD risk genes expressed in both the astrocytes [CLU, MEF2C, IQCK] and microglia [APOE, MS4A6A, PILRA]) were correlated with tissue amyloid or pTau expression. The differentially expressed genes were distinct between with the two cell types and pathologies, although common (but cell-type specific) gene sets were enriched with both pathologies in each cell type. Astrocytes showed enrichment for proteostatic, inflammatory and metal ion homeostasis pathways. Pathways for phagocytosis, inflammation and proteostasis were enriched in microglia and perivascular macrophages with greater tissue amyloid, but IL1-related pathway enrichment was found specifically in association with pTau. We also found distinguishable sub-clusters in the astrocytes and microglia characterised by transcriptional signatures related to either homeostatic functions or disease pathology. Gene co-expression analyses revealed potential functional associations of soluble biomarkers of AD in astrocytes (CLU) and microglia (GPNMB). Our work highlights responses of both astrocytes and microglia for pathological protein clearance and inflammation, as well as glial transcriptional diversity in AD.
Assuntos
Doença de Alzheimer/patologia , Astrócitos/metabolismo , Encéfalo/patologia , Microglia/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Feminino , Humanos , Masculino , TranscriptomaRESUMO
A history of safe use is a backbone of safety assessments for many current probiotic species, however, there is no global harmonization regarding requirements for establishing probiotic safety for use in foods and supplements. As probiotic manufacturers are increasingly seeking to use new strains, novel species, and next-generation probiotics, justification based on a significant history of use may be challenged. There are efforts underway by a variety of stakeholders, including the United States Pharmacopeia (USP), to develop best practices guidelines for assessing the quality and safety of probiotics. A current initiative of the USP seeks to provide expert advice specific to safety considerations for probiotics. Toward this goal, this review provides a helpful summary guide to global regulatory guidelines. We question the suitability of traditional animal toxicology studies designed for testing chemicals for relevance in assessing probiotic safety. This includes discussion of the use of excessive dose levels, the length of repeated dose toxicity studies needed, and the most suitable animal species used in toxicology studies. In addition, the importance of proper manufacturing practices with regard to final product safety are also included. Thus, an outline of essential parameters of a comprehensive safety assessment for a probiotic are provided.
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Probióticos , Animais , Probióticos/efeitos adversos , Suplementos NutricionaisRESUMO
Species of Pantoea represent a group of plant pathogenic bacteria that infect a variety of agro-economically important plant species. Among these, a complex of P. ananatis, P. allii, P. agglomerans, and P. stewartii subsp. indologenes cause center rot in onion, resulting in significant economic losses. As species of Pantoea are phenotypically closely related, identification of Pantoea species relies on the sequencing and phylogenetic analysis of housekeeping genes. To aid in rapid identification of Pantoea species, efforts have been made in developing species-specific primers to be used in PCR assays. In the current study, two P. ananatis, one P. allii, one P. agglomerans, and three P. stewartii published primers as well as newly developed P. agglomerans PagR primers were evaluated for their specificity against 79 Pantoea strains, belonging to 15 different species. To ensure that selected primers were evaluated against accurately identified species, sequencing and phylogenetic analysis of housekeeping gene infB were conducted. Thereafter, PCR assays using selected species-specific primers were performed. The results showed that previously described P. ananatis-specific PANA_1008; P. allii-specific allii-leuS; P. stewartii-specific PANST_rpoB, 3614galE, and DC283galE primers; and one newly designed P. agglomerans-specific PagR primer pair were highly specific for their target Pantoea species. They accurately identified these strains into their species and, in some cases, their subspecies level. The findings of the current study will facilitate rapid and reliable identification of P. ananatis, P. agglomerans, P. allii, and P. stewartii.
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Pantoea , Pantoea/genética , Filogenia , Reação em Cadeia da Polimerase , Especificidade da EspécieRESUMO
INTRODUCTION: Rural placements are an important component of rural medical education programs seeking to develop rural practice pathways for medical students. These placements are usually domestic, but James Cook University in Australia developed an international rural placement program in the first half of the medical course that was funded through bursaries. This study explores how the international rural placement helped to shape the lives (personal development and learning) of the participants, using Transformational Learning Theory as a framework for identifying and describing the transformational elements, process and impact of the program. METHODS: Sixty-five students received a bursary for an international rural placement between 2001-2019. All were contacted by email and invited to participate in a short survey and a follow-up interview. Fifteen participants agreed and twelve were able to participate in individual semi-structured interviews which were recorded, transcribed and analysed using inductive thematic analysis. RESULTS: Participants reported that the bursary provided a "once in a lifetime opportunity" to "experience eye-opening and culturally rich difference". Nonetheless, some elements of the placement experience presented disorientating dilemmas that triggered deep reflections and shifts in perceptions. The bursary recipients realised that "being open-minded" allowed them "enjoy good company". They were also able to assume "outsider view which allowed reassessment of their own country" and the "isolation experiences gingered desire to right health wrongs". The triggers and mental shifts had significant impact on the bursary recipients and fostered the development of "inspirational new horizons" based on an appreciation of the "value of rural practice" and "role-modelling for life-long learning." These findings are consistent with Transformational Learning Theory. CONCLUSION: Participants in this study reported meaningful and strongly positive impacts from the experiences gained during an international rural clinical placement early in their course. They described transformative experiences which appear to contribute strongly to personal development. This finding supports maintaining opportunities for international experiences during rurally-oriented medical programs as these may impact longer term career choice.